public static void RowPermute <T>(Narray <T> data, Narray <int> permutation)
{
CHECK_ARG(data.Dim(0) == permutation.Length(), "data.Dim(0) == permutation.Length()");
Narray <bool> finished = new Narray <bool>(data.Dim(0));
finished.Fill(false);
for (int start = 0; start < finished.Length(); start++)
{
if (finished[start])
{
continue;
}
int index = start;
Narray <T> value = new Narray <T>();
RowCopy(value, data, index);
for ( ; ;)
{
int next = permutation[index];
if (next == start)
{
break;
}
RowCopy(data, index, next);
index = next;
CHECK_ARG(!finished[index], "!finished[index]");
finished[index] = true;
index = next;
}
RowCopy(data, index, value);
finished[index] = true;
}
}
public static void RowGet <T, S>(Narray <T> outv, Narray <S> data, int row)
{
outv.Resize(data.Dim(1));
for (int i = 0; i < outv.Length(); i++)
{
outv[i] = (T)Convert.ChangeType(data[row, i], typeof(T));
}
}
/// <summary>
/// Reverse an array
/// </summary>
public static void Reverse <T>(Narray <T> outa, Narray <T> ina)
{
outa.Clear();
for (int i = ina.Length() - 1; i >= 0; i--)
{
outa.Push(ina[i]);
}
}
public static void RowCopy <T>(Narray <T> a, int i, Narray <T> b)
{
CHECK_ARG(a.Dim(1) == b.Length(), "a.Dim(1) == b.Length()");
for (int k = 0; k < a.Dim(1); k++)
{
a[i, k] = b[k];
}
}
public static void RowPush <T>(Narray <T> table, Narray <T> data)
{
if (table.Length1d() == 0)
{
table.Copy(data);
table.Reshape(1, table.Length());
return;
}
CHECK_ARG(table.Dim(1) == data.Length(), "table.Dim(1) == data.Length()");
table.Reserve(table.Length1d() + data.Length());
table.SetDims(table.Dim(0) + 1, table.Dim(1), 0, 0);
int irow = table.Dim(0) - 1;
for (int k = 0; k < table.Dim(1); k++)
{
table[irow, k] = data.UnsafeAt1d(k);
}
}
/// <summary>
/// Quicksort an array, generating a permutation of the indexes.
/// </summary>
public static void Quicksort <T>(Narray <int> outindex, Narray <T> values)
{
outindex.Resize(values.Length());
for (int i = 0; i < values.Length(); i++)
{
outindex[i] = i;
}
Quicksort(outindex, values, 0, outindex.Length());
}
/// <summary>
/// Find unique elements.
/// </summary>
public static void Uniq <T>(Narray <T> values)
{
if (values.Length() == 0)
{
return;
}
Quicksort(values);
int j = 1;
for (int i = 1; i < values.Length(); i++)
{
if (values[i].Equals(values[j - 1]))
{
continue;
}
values[j++] = values[i];
}
values.Truncate(j);
}
public static int first_index_of(Narray <int> a, int target)
{
for (int i = 0; i < a.Length(); i++)
{
if (a[i] == target)
{
return(i);
}
}
return(-1);
}
public static int first_index_of <T>(Narray <T> a, T target)
{
for (int i = 0; i < a.Length(); i++)
{
if (a[i].Equals(target))
{
return(i);
}
}
return(-1);
}
/// <summary>
/// Original name: randomly_permute
/// </summary>
public static void RandomlyPermute <T>(Narray <T> v)
{
int n = v.Length();
for (int i = 0; i < n - 1; i++)
{
int target = DRandomizer.Default.nrand() % (n - i) + i;
T temp = v[target];
v[target] = v[i];
v[i] = temp;
}
}
public static void Shuffle <T>(Narray <T> values)
{
Floatarray temp = new Floatarray(values.Length());
Intarray index = new Intarray();
for (int i = 0; i < temp.Length(); i++)
{
temp.UnsafePut1d(i, DRandomizer.Default.drand());
}
Quicksort(index, temp);
Permute(values, index);
}
public static float Median(Narray <int> a)
{
Narray <int> s = new Narray <int>();
s.Copy(a);
s.Reshape(s.Length1d());
Quicksort(s);
int n = s.Length();
if (n == 0)
{
return(0);
}
if ((n % 2) > 0)
{
return(s[n / 2]);
}
else
{
return((s[n / 2 - 1] + s[n / 2]) / 2.0f);
}
}
/// <summary>
/// Permute the elements of an array given a permutation.
/// </summary>
public static void Permute <T>(Narray <T> data, Narray <int> permutation)
{
if (!data.SameDims(permutation))
{
throw new Exception("CHECK_ARG: data.SameDims(permutation)");
}
Narray <bool> finished = new Narray <bool>(data.Length());
finished.Fill(false);
for (int start = 0; start < finished.Length(); start++)
{
if (finished[start])
{
continue;
}
int index = start;
T value = data[index];
for ( ; ;)
{
int next = permutation[index];
if (next == start)
{
break;
}
data[index] = data[next];
index = next;
//CHECK_ARG(!finished[index] && "not a permutation");
if (finished[index])
{
throw new Exception("CHECK_ARG: !finished[index]");
}
finished[index] = true;
index = next;
}
data[index] = value;
finished[index] = true;
}
}
public int Length()
{
return(data.Length());
}
public static void Quicksort <T>(Narray <T> values)
{
Quicksort(values, 0, values.Length());
}